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Zanjani, Esmail D.; Almeida-Porada, Graça; Flake, AW

doi:10.1016/0925-5710(96)00445-8

Cited by 81 publications

(11 citation statements)

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“…Importantly, these sheep all spontaneously develop severe, debilitating hemarthroses, making them unique among the animal models of HA. In addition to the accuracy of their clinical presentation of HA, sheep share many important physiological, developmental, and immunological characteristics with humans [8, 33-35], making them a good preclinical large animal model for developing/testing stem cell and/or gene therapy-based treatments for HA and obtaining results of high clinical significance.…”

Section: Discussionmentioning

confidence: 99%

Phenotypic correction of hemophilia A in sheep by postnatal intraperitoneal transplantation of FVIII-expressing MSC

Porada¹,

Sanada²,

Kuo³

et al. 2011

Experimental Hematology

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We recently re-established a line of sheep that accurately mimics the clinical symptoms and genetics of severe hemophilia A (HA). Herein, we tested a novel, non-ablative transplant therapy in 2 pediatric HA animals. Paternal mesenchymal stem cells (MSC) were transduced with a porcine FVIII-encoding lentivector, and transplanted via the intraperitoneal route, without preconditioning. At the time of transplantation, these animals had received multiple hFVIII treatments for various spontaneous bleeds, and had developed debilitating hemarthroses which produced severe defects in posture and gait. Transplantation of transduced MSC resolved all existent hemarthroses, and spontaneous bleeds ceased. Damaged joints recovered fully; the animals regained normal posture and gait and resumed normal activity. Despite achieving factor-independence, a sharp rise in pre-existent Bethesda titers occurred following transplantation, decreasing the effectiveness and duration of therapy. Post-mortem examination revealed widespread engraftment, with MSC present within the lung, liver, intestine, and thymus, but particularly within joints affected at the time of transplantation, suggesting MSC homed to sites of ongoing injury/inflammation to release FVIII, explaining the dramatic improvement in hemarthrotic joints. In summary, this novel, non-ablative MSC transplantation was straightforward, safe, and converted life-threatening, debilitating HA to a moderate phenotype in a large animal model.

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Section: Discussionmentioning

confidence: 99%

Phenotypic correction of hemophilia A in sheep by postnatal intraperitoneal transplantation of FVIII-expressing MSC

Porada¹,

Sanada²,

Kuo³

et al. 2011

Experimental Hematology

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“…The group of Zanjani, capitalizing on the immunologically tolerant environment of the fetal sheep between 50 and 60 days of gestation, successfully showed engraftment and persistence of human cells several years after intraperitoneal administration in utero of primitive human hematopoietic cells from CB or BM. 93–95 Among fetuses reaching maturity, at least 50% showed long-term persistence of human cells and demonstration that retrovirally transduced human cells could be detected, 96 suggesting transduction of primitive human HSCs. However, the procedure was hampered by low-level engraftment, a high rate of fetal loss, and impracticality for most research groups.…”

Section: Development Of Methodologies For the Genetic Manipulation Ofmentioning

confidence: 99%

Hematopoietic Stem Cell Gene Therapy: Assessing the Relevance of Preclinical Models

Larochelle

Dunbar

2013

Seminars in Hematology

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The modern laboratory mouse has become a central tool for biomedical research with a notable influence in the field of hematopoiesis. Application of retroviral-based gene transfer approaches to mouse hematopoietic stem cells (HSCs) has led to a sophisticated understanding of the hematopoietic hierarchy in this model. However, the assumption that gene transfer methodologies developed in the mouse could be similarly applied to human HSCs for the treatment of human diseases left the field of gene therapy in a decade-long quandary. It is not until more relevant humanized xenograft mouse models and phylogenetically related large animal species were used to optimize gene transfer methodologies that unequivocal clinical successes were achieved. However, the subsequent reporting of severe adverse events in these clinical trials casted doubts on the predictive value of conventional pre-clinical testing, and encouraged the development of new assays for assessing the relative genotoxicity of various vector designs.

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“…The fetal sheep model has proven to be an appropriate model for the assessment of in-vivo cell fate and bio-distribution of human cells with specific regards to survival and engraftment [10]–[12], [14], [16]. In contrast to other animal models either being genetically modified (i.e.…”

Section: Methodsmentioning

confidence: 99%

“…nude mice) or requiring immunosuppressive therapy (xenogenic models such as adult porcine or ovine models) for the assessment of human stem cells, the fetal sheep has a normal functioning immune system, but is still able to support cell engraftment and survival if the cells are transplanted before day 75 of gestation (term 145 days). Taking advantage of this “window of opportunity” and this “pre-immune” period of development, this model allows for a significant engraftment of human cells without the necessity of immunosuppressive therapy [8]–[12], [14], [16].…”

Section: Methodsmentioning

confidence: 99%

“…Although the fetal sheep has a normal functioning immune-system, it is still able to support human cell engraftment and differentiation if the cells are transplanted before day 75 of gestation [8]–[11], [16]. Following ultrasound-guided, intra-peritoneal stem cell transplantation, previous reports have shown that the fetal sheep is immunologically tolerant to human skin grafts and to allogenic or xenogenic stem cells during this “pre-immune” period of development allowing for a significant engraftment of human cells without the necessity of immunosuppressive therapy [8], [9], [16]–[23]. Taking this unique advantage of this pre-immune status as well as the large size and the long life-span into account, the fetal sheep represents an highly interesting animal model to study human cell-fate offering experimental opportunities that are not available in murine models [10], [11], [16].…”

Section: Introductionmentioning

confidence: 99%

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Intramyocardial Transplantation and Tracking of Human Mesenchymal Stem Cells in a Novel Intra-Uterine Pre-Immune Fetal Sheep Myocardial Infarction Model: A Proof of Concept Study

et al. 2013

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Although stem-cell therapies have been suggested for cardiac-regeneration after myocardial-infarction (MI), key-questions regarding the in-vivo cell-fate remain unknown. While most available animal-models require immunosuppressive-therapy when applying human cells, the fetal-sheep being pre-immune until day 75 of gestation has been proposed for the in-vivo tracking of human cells after intra-peritoneal transplantation. We introduce a novel intra-uterine myocardial-infarction model to track human mesenchymal stem cells after direct intra-myocardial transplantation into the pre-immune fetal-sheep. Thirteen fetal-sheep (gestation age: 70–75 days) were included. Ten animals either received an intra-uterine induction of MI only (n = 4) or MI+intra-myocardial injection (IMI;n = 6) using micron-sized, iron-oxide (MPIO) labeled human mesenchymal stem cells either derived from the adipose-tissue (ATMSCs;n = 3) or the bone-marrow (BMMSCs;n = 3). Three animals received an intra-peritoneal injection (IPI;n = 3; ATMSCs;n = 2/BMMSCs;n = 1). All procedures were performed successfully and follow-up was 7–9 days. To assess human cell-fate, multimodal cell-tracking was performed via MRI and/or Micro-CT, Flow-Cytometry, PCR and immunohistochemistry. After IMI, MRI displayed an estimated amount of 1×105–5×105 human cells within ventricular-wall corresponding to the injection-sites which was further confirmed on Micro-CT. PCR and IHC verified intra-myocardial presence via detection of human-specific β-2-microglobulin, MHC-1, ALU-Sequence and anti-FITC targeting the fluorochrome-labeled part of the MPIOs. The cells appeared viable, integrated and were found in clusters or in the interstitial-spaces. Flow-Cytometry confirmed intra-myocardial presence, and showed further distribution within the spleen, lungs, kidneys and brain. Following IPI, MRI indicated the cells within the intra-peritoneal-cavity involving the liver and kidneys. Flow-Cytometry detected the cells within spleen, lungs, kidneys, thymus, bone-marrow and intra-peritoneal lavage, but not within the heart. For the first time we demonstrate the feasibility of intra-uterine, intra-myocardial stem-cell transplantation into the pre-immune fetal-sheep after MI. Utilizing cell-tracking strategies comprising advanced imaging-technologies and in-vitro tracking-tools, this novel model may serve as a unique platform to assess human cell-fate after intra-myocardial transplantation without the necessity of immunosuppressive-therapy.

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Cited by 81 publications

References 0 publications

Phenotypic correction of hemophilia A in sheep by postnatal intraperitoneal transplantation of FVIII-expressing MSC

Phenotypic correction of hemophilia A in sheep by postnatal intraperitoneal transplantation of FVIII-expressing MSC

Hematopoietic Stem Cell Gene Therapy: Assessing the Relevance of Preclinical Models

Intramyocardial Transplantation and Tracking of Human Mesenchymal Stem Cells in a Novel Intra-Uterine Pre-Immune Fetal Sheep Myocardial Infarction Model: A Proof of Concept Study

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